Objective-To use linked assisted reproductive technology (ART) surveillance and birth certificate data to compare ET practices and perinatal outcomes for a state with a comprehensive mandate requiring coverage of IVF services versus states without a mandate. Design-Retrospective cohort study. Setting-Not applicable.Patient(s)-Live-birth deliveries ascertained from linked 2007-2009 National ART Surveillance System and birth certificate data for a state with an insurance mandate (Massachusetts) and two states without a mandate (Florida and Michigan). Intervention(s)-None.Main Outcome Measure(s)-Number of embryos transferred, multiple births, low birth weight, preterm delivery. Result(s)-Of